One of the major technological challenges currently throughout the world in naturally fractured carbonate reservoirs (NFCR) with high-temperature and an ultra-high salinity condition is to increase the hydrocarbon recovery factor using chemical products. NFCRs are characterized for possessing low porosity, for having preferential flow areas, due to the existence of fractures and dissolution cavities and for exhibiting wettability to oil or intermediate ones. Therefore, chemical products used therein in order to increase the recovery factor must be able to control the channeling of fluids and to alter the rock wettability from oil-wettable to water-wettable. Moreover, if the NFCRs have conditions of high temperature and salinity, chemical products to be used in enhanced recovery processes are required to be tolerant to high salinities and divalent ions concentrations and to control corrosion problems occurring in the production rigs
The traditional way to control the channeling of fluids in NFCRs has been by means of the use of foaming agents and/or gels [SPE 145718, 2011, Development of a new foam EOR model from laboratory and field data of the naturally fractured Cantarell Field; SPE 130655, 2010, High-temperature conformance field application through coiled tubing a successful case history; SPE 129840, 2010, Application of gas for mobility control in chemical EOR in problematic carbonate reservoirs] and the performance thereof is a function of the reservoir's temperature, salinity and concentration of divalent ions present in the injection water and/or formation water, and of the type of crude oil present in the reservoir. Furthermore, the benefits of using foaming agents with wettability-modifying properties that control gas channeling problems and increase the recovery factor in NFCRs has been recently demonstrated in Mexico [AIPM, 13-33, 2012, Control de movilidad del gas en el casquete en pozos del cameo Akal perteneciente al Complejo Cantarell; SPE 145718, 2011, Development of a new foam EOR model from laboratory and field data of the naturally fractured Cantarell Field;] and the development of foaming agents with enhanced stabilities with wettability-modifying properties and the ability to control corrosion problems occurring in production rigs has been established as a challenge.
The main chemical families of surfactants that have been used to generate foams and that have application in enhanced recovery processes include: 1) Alkyl aryl sulfonates (U.S. Pat. No. 5,273,682; Viscosity control additives for foaming mixtures), 2) Alkoxy alkyl benzenesulfonates (U.S. Pat. No. 5,049,311; Alkoxylated alkyl substituted phenol sulfonates compounds and compositions, the preparation thereof and their use in various applications), 3) Alpha olefin sulfonates (U.S. Pat. No. 4,607,695; High sweep efficiency steam drive oil recovery method), 4) Alkyl amido Betaines (U.S. Pat. No. 7,104,327; Methods of fracturing high temperature subterranean zones and foamed fracturing fluids therefor), 5) Alkyl amido hydroxysultaines (U.S. Pat. No. 7,407,916; Foamed treatment fluids and associated methods) and 6) Alkyl ether sulfates (Report DE-FC26-03NT15406 by the Department of Energy of the United States of America Surfactant-Based Enhanced Oil Recovery Processes and Foam Mobility Control). However, when the conditions of temperature in the reservoirs are elevated (higher than 70° C.), salinity is higher than 30,000 ppm of total solids and the concentration of divalent ions such as calcium and magnesium is higher than 2,000 ppm, the stability of the foam generated by this class of surfactants chemical families decreases drastically.
In order to increase the stability of foams and hence their tolerances to high concentrations of divalent ions and/or temperature, foaming agents' formulations with enhanced properties have been developed, including as the following:
U.S. Pat. No. 3,939,911 (Surfactant oil recovery process usable in high temperature formations containing water having high concentrations of polyvalent ions) describes a three-surfactant system applied to enhanced recovery processes in reservoirs with high temperature and formation water containing from 200 to 14,000 ppm of polyvalent ions dissolved, such as calcium or magnesium. The three-surfactant system is composed by: 1) A water-soluble salt of an alkyl or alkyl aryl sulfonate, wherein the alkyl chain can have from 5 to 25 carbon atoms, 2) A phosphate ester surfactant with an average molecular weight not exceeding 1,000 AMU and 3) A sulfobetaine-based surfactant having the structural formula (2) and wherein R is an alkyl group of 12 to 24 carbon atoms. The combination is stable up to a temperature of 107° C. and resistant to bacterial attacks and inhibits the formation of scale.

U.S. Pat. No. 4,703,797 (Sweep improvement in enhanced oil recovery) mentions a new enhanced method for sweeping during enhanced hydrocarbon recovery processes. The method comprises the generation of foam by means of dispersion of the displacement fluid in an aqueous solution containing a formulation of surfactants. Said surfactant formulation comprises a lignosulfate-based foaming agent and a foaming surfactant. The foaming surfactants that are mentioned include the group comprising anionic, non-ionic and amphoteric surfactants.
U.S. Pat. No. 5,295,540 (Foam mixture for steam and carbon dioxide drive oil recovery method) mentions a method based on foams to enhance hydrocarbon production in subterranean formations consisting of: 1) Injecting steam and produced fluids into the formation and 2) Injecting a mixture of steam, a non-condensable gas and an aqueous mixture of surfactant and polysaccharides. The surfactants mentioned that may be used include linear toluene sulfonates, alkyl aryl sulfonates, dialkyl aryl sulfonates, alpha olefin sulfonates and alpha olefin sulfonate dimers.
U.S. Pat. No. 5,542,474 (Foam mixture for carbon dioxide drive oil recovery method) refers to a foam-based method to enhance performance during the supply of steam or carbon dioxide in subterranean formations containing crude oil and that comprise at least a producing well and an injection well. The sweeping efficiency in the oil-recovery process by means of steam supply is enhanced by: 1) injecting steam until it starts to appear in the producing well and 2) Subsequently adding a mixture of steam, non-condensable gas and an aqueous solution of a surfactant-polypeptide. The aqueous surfactant-polypeptide solution forms stable foam with the formation oil at reservoir conditions. Surfactants used as base for the foaming agent include sodium and ammonium salts of sulfated alcohol ethoxylates, linear alcohol ethoxylates and linear toluene sulfonates.
The article “Improving the foam performance for mobility control and improved sweep efficiency in gas flooding” (Ind. Eng. Chem. Res. 2004, 43, 4413-4421) mentions that the apparent stability and viscosity of a foam generated by alpha olefin sulfonates in brine having concentrations of 30,000 and 120,000 ppm of total solids dissolved is substantially enhanced when formulated with partially hydrolyzed polyacrylamide-based polymers or xanthan gum-type biopolymers. Furthermore, the article mentions that the stability of foams generated by twelve-carbon alpha olefin sulfonates is substantially increased when formulated with amine oxide-type surfactants.
U.S. Pat. No. 5,911,981 (Surfactant blends for generating stable wet foam) mentions a mixture of surfactants that generates stable spherical foams. The mixture of surfactants contains a non-ionic surfactant or an amphoteric surfactant as the primary foaming agent, and sufficient amounts of an acyl lactylate to increase the volume of the foam and to provide an excess of spherically-shaped foam for time periods of approximately forty minutes. The amphoteric surfactants that are mentioned include betaines, sultaines and aminosultaines and the use of cocodimethylpropylsultaine, stearyldimethylpropylsultaine, lauryl-bis (2 hydroxyethyl)propylsultaine and cocoamidopropyl hydroxysultaine is specifically mentioned.
U.S. Pat. No. 7,104,327 provides methods to fracture high-temperature subterranean zones and foamed aqueous and viscous fracturing fluids for this purpose. The fracturing fluid of said invention comprises water, a 2-acrylamide-2-methylpropane sulfonic acid terpolymer, acrylamide and acrylic acid or salts thereof, a gas, a foaming agent and a viscosity breaker to control and reduce the viscosity of the fracturing fluid. The foaming agent in said invention is selected from the group comprising C8-C22 alkyl amido betaine, alpha olefin sulfonate, taloil trimethyl ammonium chloride, C8-C22 alkyl ethoxylate sulfate and trimethyl coco ammonium chloride and special mention is made of cocoamidopropyl betaine as foaming agent.
The synergystic effect of alkyl amido propyl betaines with alkyl ether sodium sulfate and alkyl sodium sulfate-type anionic surfactants has been studied in literature (Langmuir 2000, 16, 1000-1013, Langmuir 2004, 20, 565-571, Langmuir 2004, 20, 5445-5453) and it primarily suggests the ability of alkyl amido propyl betaines to stabilize and to improve the rheological properties (viscosity) of foams generated by the anionic surfactants and that have application in shampoos and hair conditioners. Furthermore, the article “Synergistic sphere-to-rod micelle transition in mixed solutions of sodium dodecyl sulfate and cocoamidopropyl betaine” (Langmuir 2004, 20, 565-571) indicates that the synergistic effect between cocoamidopropyl betaine and dodecyl sodium sulfate is due to an electrostatic attraction between both surfactants' heads (3).

U.S. Pat. No. 7,134,497 (Foamed treatment fluids and associated methods) mentions fluids for foamed treatments comprising water, a gas and a foam and mixtures of foam stabilizing surfactants comprising an alkali salt of an alkyl ether sulfate, wherein the alkali salt of the alkyl ether sulfate comprises an alkali salt of a C6-10 alkyl ether sulfate and an alkali salt of a C4 alkyl ether sulfate, an alkyl amidopropyl amphoteric surfactant selected from the group consisting of an alkyl amidopropyl hydroxysultaine, an alkyl amidopropyl betaine and a combination thereof, and an alkyl amidopropyl dimethylamine oxide. The patent comprises methods to generate fluids for foamed treatments and to introduce them in subterranean formations. Furthermore, U.S. Pat. No. 7,134,497 never mentions the use of sodium alkyl hydroxysulfonates and/or sodium alpha olefin sulfonates, or that the fluids for the foamed treatments have wettability modifying or corrosion inhibitory properties.
U.S. Pat. No. 7,287,594 (Foamed Treatment Fluids and Associated Methods) refers to treatment methods for subterranean formations using foamed fluids comprising water, a gas and a foam, and mixtures of foam stabilizing surfactants comprising a range of alkali salts of alkyl ether sulfates, wherein the alkyl group in each of the alkyl ether sulfates is in the range of 4 carbon atoms to 10 carbon atoms, an alkyl amido propyl hydroxysultaine or an alkyl amido propyl betaine and an alkyl amido propyl dimethylamine oxide. The patent does not mention the use of sodium alkyl hydroxy sulfonates and/or sodium alpha olefin sulfonates or that the foamed fluids have wettability-modifying or corrosion inhibitory properties.
U.S. Pat. No. 7,373,977 (Process for Oil Recovery Employing Surfactant Gels) protects a hydrocarbon recovery composition and process, which comprise injecting an aqueous solution into a hydrocarbon-containing formation through one or more injection wells, displacing the solution within the formation and recovering the hydrocarbon through one or more producing wells. The aqueous solution contains one or more amphoteric surfactants of the alkyl amido betaines-type (4) that form a viscoelastic surfactant gel that can reduce interfacial tension and increase injection fluid viscosity simultaneously in certain oils and brines. Viscoelastic gels are tolerant to multivalent electrolytes and cations and are particularly useful within reservoirs with middle to high temperature, high salinities, high concentrations of divalent ions and low porosity. The application mentions that the hydrocarbon-recovery compound contains one or more amphoteric surfactants selected for their ability to lower interfacial tension and to increase viscosity simultaneously, an aqueous medium, a secondary surfactant and, optionally, one or more polymers to provide residual viscosity. The patent application indicates that the secondary surfactant can be selected from the anionic, cationic or non-ionic group and that the polymer that provides residual viscosity is selected from the group of polyacrylamide, partially hydrolyzed polyacrylamide, xanthan gum, hydroxyethyl cellulose or guar gum. Additionally, the patent application mentions that the combination of alkyl amido betaines with secondary surfactants of the linear type sodium dodecyl benzene sulfonate and sodium arylalkyl xylene sulfonate reduces interfacial tension and increases the viscosity of the system.

U.S. Pat. No. 7,407,916 (Foamed treatment fluids and associated methods) mentions fluids for foamed treatments containing water, a gas and a foam and mixtures of foam stabilizing surfactants comprising an alkali salt of an alkyl ether sulfate, wherein the alkali salt of the alkyl ether sulfate comprises an alkali salt of a C6-10 alkyl ether sulfate and an alkali salt of a C4 alkyl ether sulfate, an alkyl amido propyl amphoteric surfactant selected from the group comprising an alkyl amido propyl hydroxysultaine, an alkyl amido propyl betaine and a combination thereof, and an alkyl amido propyl dimethylamine oxide. The patent includes methods to generate fluids for foaming treatments and to introduce them in subterranean formations. Additionally, U.S. Pat. No. 7,407,916 never mentions the use of sodium alkyl hydroxysulfonates and/or sodium alpha olefin sulfonates, or that the fluids for foamed treatments have wettability modifying or corrosion inhibitory properties.
Mexican patent MX 297297 relates to an enhanced-stability foaming composition that controls gas channeling in naturally fractured carbonate reservoirs with high salinity and temperature conditions, by means of the synergistic effect resulting from the supramolecular interaction of sodium alpha olefin sulfonates with alkyl amido propyl betaines (5),
wherein R and R1 are independent linear or branched alkyl chains with a length ranging from 1 to 30 carbon atoms. The patent application mentions that the supramolecular complexes resulting from the interaction of sodium alpha olefin sulfonates with alkyl amido propyl betaines can be combined with anionic surfactants, preferably of the sodium 3-hydroxy-alkyl sulfonate-type, with cationic surfactants such as alkyl ammonium quaternary salts, preferably of the alkyl trimethyl ammonium chloride- or bromide-type, with divalent ions sequestrants, preferably itaconic acid-derived oligomers or copolymers and whose average molecular weight is within the range of 200 to 20,000 Daltons, with gels derived from copolymers selected from the group comprising polyacrylamides, partially hydrolyzed polyacrylamide, xanthan gum, Poly(itaconic acid), Poly(acrylic acid), Poly(itaconic acid-co-acrylic acid) poly(itaconates) and Poly(acrylates). Additionally, the patent application indicates that the enhanced-stability foaming compositions have applications in enhanced recovery and/or production assurance processes. The patent application does not mention using alkyl amido propyl hydroxysultaine or alkyl hydroxysultaine-based compositions or that these have applications as wettability modifiers and corrosion inhibitors.
Regarding the use as wettability modifiers with applications in enhanced recovery processes, specialized literature mentions that the main surfactant families that have been used are: 1) Tetra-alkyl ammonium quaternary salts (Energy & Fuel 2011, 25, 2083-2088; Combined Surfactant-Enhanced Gravity Drainage (SEGD) of Oil and the Wettability Alteration in Carbonates: The Effect of Rock Permeability and Interfacial Tension (IFT)), 2) Ethoxylated alcohols (Energy & Fuel 2002, 16, 1557-1564; An Evaluation of Spontaneous Imbibition of Water into Oil-Wet Carbonate Reservoir Cores Using a Nonionic and a Cationic Surfactant), 3) Alkyl ether sulfates alkaline salts (US Patent Publication 2011/0071057; Method of Manufacture and Use of Large Hydrophobe Ether Sulfate Surfactants in Enhanced Oil Recovery (EOR) Applications; Langmuir 2008, 24, 14099-14107; Mechanistic Study of Wettability Alteration Using Surfactants with Applications in Naturally Fractured Reservoirs), 4) Sodium alkyl aryl sulfonates (U.S. Pat. No. 4,836,283, Divalent Ion Tolerant Aromatic Sulfonates), 5) Internal sodium olefin sulfonates (SPE 115386, Recent Advances in Surfactant EOR), 6) Betaines (Energy & Fuel 2011, 25, 2551-2558; Wettability Alteration of Clay in Solid-Stabilized Emulsions).
Additionally, in order to increase the performance of wettability modifiers, formulations with enhanced properties have been developed, such as the following:
U.S. Pat. No. 4,270,607 (Emulsion Oil Recovery Process Usable in High Temperature, High Salinity Formations) mentions the fact that many formations contain water with high levels of salinity and/or concentrations of divalent ions such as calcium or magnesium, and additionally, they have temperatures ranging from 21° C. to 149° C. In addition, it indicates that most surfactants and polymers that are adequate for the generation of fluids or emulsions used in enhanced recovery operations do not perform adequately at high levels of salinity or hardness of the water, or do not tolerate the high temperatures found in many formations. Furthermore, it mentions that a viscous emulsion containing a water-soluble and/or dispersible alkyl aryl polyalkoxyalkylene sulfonate and a phase stabilizing additive such as water-soluble and/or dispersible petroleum sulfonate is an effective fluid to be injected in oil formations containing brines whose salinity is within the range of 70,000 to 220,000 ppm of total solids dissolved and where temperatures are as high as 149° C. The emulsion is a stable phase over a wide range of temperatures, formations and salinity and hardness values that can be found in water.
U.S. Pat. No. 6,828,281 (Surfactant Blends for Aqueous Solutions Useful for Improving Oil Recovery) mentions an aqueous fluid useful for liquid hydrocarbon recovery in subterranean reservoirs and where the aqueous fluid comprises an aqueous medium and a mixture of surfactants. The mixture of surfactants contains at least a polyisobutylene-based synthetic surfactant and a secondary surfactant selected from the group comprising sulfonated surfactants, alcohols and ionic surfactants. The surfactant mixture lowers interfacial tension between the hydrocarbon and the aqueous fluid.
US Patent Publication 2009/0111717 (Enhanced Oil Recovery Surfactant Formulation and Method of Making the Same) mentions enhanced hydrocarbon recovery formulations comprising: a) An alkyl aryl sulfonate, b) An isomerized olefin sulfonate, c) A solvent, d) A passivator and e) A polymer.
On the other hand, and due to the impact of the wettability phenomenon on enhanced recovery processes, different institutions and companies have worked at international level in the development of new chemical structures with enhanced properties, and as examples we can quote U.S. Pat. No. 7,629,299 (Process for Recovering Residual Oil Employing Alcohol Ether Sulfonates) and patent application MX/a/2010/012348 (Composición Base Liquidos Zwitteriónicos Geminales como Modificadores de la Mojabilidad en Procesos de Recuperación Mejorada del Petróleo).
With regard to the use as corrosion inhibitors with application in hydrocarbon exploitation and transportation processes, specialized literature mentions that the main chemical products families that have been used are: 1) 1-heteroalkyl-2-Alkyl Imidazolines (Patent MX 254565, Composición Inhibitoria de la Corrosion para Metales Ferrosos en Medios Ácidos; Patent MX 260049, ComposiciOn Inhibitoria de la Corrosión y el Ampollamiento por Hidrógeno para Metales Ferrosos en Medios Básicos), 2) Alkyl Amido Amines (Revista de la Sociedad Química de México 2002, 46, 4, 335-340, Control de la Corrosión de Acero al Carbón en Ambientes de Ácido Sulfhídrico por 1-(2-Hydroxietil)-2-Alquil-imidazolinas y sus correspondientes Precursores Amídicos; Applied Surface Science 2006, 252, 6, 2139-2152, Surface Analysis of Inhibitor Films Formed by Imidazolines and Amides on Mild Steel in an Acidic Environment), 3) Polyalkylene polyamines (U.S. Pat. No. 4,900,458, Polyalkylenepolyamines as Corrosion Inhibitors; U.S. Pat. No. 4,275,744, Derivatives of Polyalkylenepolyamines as Corrosion Inhibitors), 4) Acetylenic alcohols (U.S. Pat. No. 5,084,210, Corrosion inhibitors), 5) Diacetylenic alcohols (U.S. Pat. No. 4,039,336, Diacetylenic Alcohol Corrosion inhibitors), 6) Quaternary Ammonium Salts (U.S. Pat. No. 6,521,028, Low Hazard Corrosion Inhibitors and Cleaning Solutions Using Quaternary Ammonium Salts), 7) Bis-imidazolines (Patent MX 246603, Inhibidores de la Corrosión Multifuncionales, Biodegradables y de Baja Toxicidad) and 8) Bis-Quaternary Ammonium Salts (US Patent Publication 2006/0013798, Bis-Quaternary Ammonium Salt Corrosion Inhibitors).
In addition to this, and due to the impact that 1-heteroalkyl-2-Alkyl Imidazolines have had in the oil industry, several companies have managed to increase their water solubility by: 1) Performing their quaternization, thus generating quaternary salts (U.S. Pat. No. 6,475,431, Corrosion Inhibitors with Low Environmental Toxicity), 2) Introducing ethoxy groups in their structure (U.S. Pat. No. 5,785,895, Biodegradable Corrosion Inhibitors of Low Toxicity) and 3) Generating zwitterion ions through quaternization processes (U.S. Pat. No. 6,303,079, Corrosion Inhibitor Compositions).
Additionally, and due to the impact that the corrosion phenomenon has in the oil industry when there is high salinity and divalent ions concentrations, different institutions and companies have worked at international level in the development of new chemical structures with enhanced properties and as examples we can quote U.S. Pat. No. 8,105,987 (Corrosion Inhibitors for an Aqueous Medium) and US Patent Publication 2011/0138683 (Gemini Surfactants, Process of Manufacture and Use as Multifunctional Corrosion Inhibitors).
On the other hand, supramolecular chemistry is the part of chemistry that takes care of the study of systems that involve molecules or ions aggregates that are bound through non-covalent interactions, such as electrostatic interactions, hydrogen bonds, P—P interactions, dispersion interactions and hydrophobic effects. Supramolecular chemistry can be divided in two large areas: 1) Host-Guest Chemistry and 2) Self-assembly. The difference between these two large areas is a matter of size and form; where there is no significant difference in size and none of the species acts as host to the other, the non-covalent bonding between two or more species is termed self-assembly.
From the energetic point of view, supramolecular interactions are much weaker than covalent interactions, which fall in the energetic range of 150 to 450 Kj/mol for simple bonds. The non-covalent interactions energetic range goes from 2 kj/mol for dispersion interactions to up to 300 kj/mol for ion-ion interactions (Table 1), and the sum of several supramolecular interactions can produce highly stable supramolecular complexes.
TABLE 1Supramolecular Interactions StrengthInteractionStrength (Kj/mol)Ion-ion200-300 Ion-dipole50-200Dipole-dipole5-50Hydrogen bond 4-120Cation-p5-80p-p0-50Van der Waals<5HydrophobicRelated with the solvent-solventinteraction energy
Computational chemistry is a tool that is widely used throughout the world to predict the stability and structure of chemical systems with enhanced potential properties and has found application at industrial level in the development of quantitative structure-activity relationship studies. Computational calculation methods that have been used for this purpose include molecular mechanics methods, quantum methods, which comprise semi-empiric and ab-initio methods, as well as the density functional theory methods. As examples in literature demonstrating the use of computational chemistry to accurately predict supramolecular interactions in chemical systems and/or thermodynamic and kinetic aspects of chemical processes, the following articles can be quoted: 1) Cornucopian Cylindrical Aggregate Morphologies from Self-Assembly of Amphiphilic Triblock Copolymer in Selective Media (Journal of Physical Chemistry B, 2005, 109, 21549-21555), 2) Density Functional Calculations, Synthesis, and Characterization of Two Novel Quadruple Hydrogen-Bonded Supramolecular Complexes (Journal of Physical Chemistry A, 2004, 108, 5258-5267), 3) Strong Decrease of the Benzene-Ammonium Ion Interaction upon Complexation with a Carboxylate Anion (Journal of American Chemical Society, 1999, 121, 2303-2306).
It is important to highlight that none of the aforementioned references addresses the generation and use of foaming compositions with wettability modifying and corrosion inhibitory properties that control the channeling of fluids in naturally fractured carbonate reservoirs, alter the wettability of the rock in a favorable way in crude oil enhanced recovery processes and control uniform corrosion problems occurring in production rigs under high temperature and ultra-high salinity conditions; by means of the synergistic effect resulting from the supramolecular interaction of alkyl amido propyl hydroxysultaines or alkyl amino hydroxysultaines with sodium alkyl hydroxyl sulfonates and sodium alpha olefin sulfonates; and that, to our knowledge, this is the first time that supramolecular complexes with the aforementioned properties have been developed worldwide. Additionally, the supramolecular complexes of the present invention generate foams that show superior stabilities with regard to those generated by products currently used for this purpose throughout the world.